James Turrell’s Roden Crater is a massive artwork that’s literally inside a volcano. It’s still in construction, but the inside of the crater has been engineered into tunnels and apertures that transform as the light from the environment changes (throughout the day as well as throughout the span of a geologic time scale). It’s an interesting example of an artist who was extremely intentional about the location of his piece, and who really incorporated the environment into the its physical presence and its meaning.